Valve for steam-engines



(No Model.) 2 Sheets-Sheet l.

M. 0. BULLOCK. VALVE FOR STEAM ENGINES.

NO. 407,994. Patented July 30, 1889.

N. PETERSv PhotmLilhngI-uphar, Wachinglon, D .C.

(-No Model.) 2 Sheets-Sheet 2. M. O. BULLOCK.

VALVE FOR STEAM ENGINES.

No. 407,994. Patented July 30, 1889.

N Pains. Pholo-Lihwg nphef, Wnhington, nc

UNITED STATES PATENT OF ICE.

MILAN C. BULLOCK, OF CHICAGO, ILLINOIS.

VALVE FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 407,994, dated July 30, 1889.

Application filed September 6, 1887. Serial No. 248,942. (No model.)

My invention has for one of its objects to provide for a partial steam-balance of a slidevalve and for'another to lessen the distancebetween the valve seat or bottom of the steamchest and the bore of the cylinder, whereby the steam-passages leading from the steamchest to the piston-chamber or cylinder-bore are reduced to their minimum length.

To these and other ends, which will hereinafter further appear, my invention consists in the matters set forth in the following description and pointed out in the appended claims.

In the drawings, Figure 1 is a plan of the valve-seat, showing the several ports in the same,the steam-chest being removed. Fig. 2 is a top view of the slide-valve of myimproved construction. Fig. 3 is a view of the sliding face of the valve, showing its several ports and the central chamber by which the partial balancing-of the valve by steam-pressure is attained. Fig. 4 is a central transverse section of the engine-cylinder, the steam-chest, and the valve; and Fig. 5 is a central longitudinal section of the cylinder, steam-chest, and valve.

A represents the cylinder of a steam-engine, B the steam-chest, and C a slide-valve. The valve-seat A on the cylinder-casting is provided with transverse steam-ports A in the usual positions and a longitudinally-arranged exhaust-port A placed at one side of the steam-chest or valve-seat,as seen in Figs. 1 and at. I

The slide-valve C is provided with exhaustports C C, in proper position to work in connection with the ports A in the valve-seat, which ports C communicate with an interior chamber C in the valve, having a discharge opening or port C arranged longitudinally of the valve or at right angles with the ports C and at one side of the valve in position to coincide with the port A in the valve-seat.

The valve C has apassage through it (here shown in the form of a notch or recess C) at the side thereof opposite the port C as seen in Figs. 2, 3, and 4, and this passage is extended in the under face of the valve, forming a shallow chamber C (Seen in Figs. 3, 4, and 5.) By means of this chamber C, communicating through the passage C with the general interior of the steam-chest B, steam is admitted beneath the valve to the extentof the horizontal area of this chamber, and to a corresponding extent the steam so admitted below the valve counterbalances the pressure of the steam upon the top of the valve, while the top pressure is also lessened to the extent of the passage 0*. The chamber C is located about centrally of the valve, in order that the relief afforded thereby shall be distributed in its effects of wear and friction about equally over the entire valve-face. Said chamber C may in practice be made somewhat deeper in proportion than shown in Figs. 4 and 5 of the drawings. As here illustrated, and as an additional improvement, a transverse recess A is provided in the cylindercasting centrally between the ports A and extending beyond the chamber C into free communicationwith the passage C, whereby steam is more freely admitted beneath the valve. The relation of the recess A to the notch C in the seat of the valve is shown clearly by dotted lines in Fig. 2, from which it will be seen that steam has ready access to the chamber C by said recess A A tube C extends through the chamber C of the valve C, fitted steam-tight at its ends in the end walls of the valve. This tube gives passage to the valve-stem D, upon which the valve is adjustably secured by the nuts cl (I, applied to the stem D, one at each end of the valve. The tube C is made of larger interior diameter than the stem C, for the purpose of allowing a vertical movement of the valve without a corresponding movement of the stem, as may be required by the wear of the valve face and seat or by the presence of water in the cylinder in starting the engine, which may cause the valve to rise clear of it's seat to give escape to the water.

On the top of the valve is provided an oblong plane surface 0, Figs. 2, 4, and 5, finished parallel with the valve-face. Upon this surface bears a button E, laterally confined in a socket F in the under surface of the top plate of the valve-chest B, and between said but ton E and the said top plate of the chest B is placed a spring G, Figs. 4 and 5, which eX- erts its force to press the valve against its seat.

In the construction of the valve as shown the ports of the cylinder may be direct, or as nearly direct as desired, in their course through the cylinder-wall, and the central chamber heretofore provided in the cylindercasting for the exhaust over the highest line of the cylinder-bore is dispensed with. As a result the cylinder-passages are shortened both by their more direct course and by the thinner body of metal required between the cylinder-bore and the valve-seat, the advantage of which is manifest to those acquainted with the art.

I claim as my invention 1. The combination, with a steam-engine cylinderprovided with a flat valve-seat having transversely-arranged ports A A near the ends of the cylinder and alongitudinallyarranged exhaustport A, located at one side of the valve-seat and communicating with an exhaust-passage cast in the metal of the cylinder, of a chambered slide-valve having a flat bearing-face in contact with the valveseat, and provided in said bearing-face with ports 0 C and 0 operating in connection with the ports A A A substantially as described.

2. The combination, with a stea1nengine' cylinder provided with a flat valve-seat havmg transversely-arranged ports A A near the ends of the cylinder and a longitudinallyarranged exhaust-port A located at one side of the valve-seat, of a chambered slide-valve having a flat bearing-face in contact with the valve-seat, provided in said bearing-face with transverse ports 0 0 near its ends and an intermediate longitudinally-arranged port C at one side, and having acentral recess or chamber 0 located in the flat face of the valve between said ports and in communication with the steam-space of the valve-chest at the side of the valve opposite the said port 0 3. The combination, with a steam-engine cylinder provided with a flat valve-seat having transversely-arranged ports A A near the ends of the cylinder and alongitudinallyarranged exhaust-port A located at one side of the yalve-seat, of a chambered slide-valve having a flat bearing-face in contact with the valve-seat, and provided in said bearing-face with transverse ports 0 O and with a longitudinally-arranged port 0 located at one side of the valve-seat, said valve being also provided with a recess C extending through the valve from top to bottom surface thereof in the side of the same opposite said port C substantially as described,

4:. The combination, with a valve-seat provided with steam-ports A a side exhaust-port A and a central iransverse recess A, of a slide-valve having a chamber C and a passage C, communicating with said chamber and with the recess A substantially as described.

In testimony that I claim the foregoing as myinvention I affix my signature in presence of two witnesses.

MILAN C. BULLOCK.

WV i tn esses:

M. E. DAYTON, G. CLARENCE PooLE. 

